Response of growth and chlorophyll fluorecence characteristics of Cynodon dactylon seedlings to water treatment and plant densities

In order to explore the effects of different water treatments and plant densities on growth, photosynthetic pigments and chlorophyll fluorescence of Cynodon dactylon, 4 water treatments and 4 planting densities including 16 treatments were applied. The water treatments included normal water supply (CK), light floodinglight drought alternating (FD), light flooding (LF) and flooding (FL) and planting densities included 1 plant per pot (CK), 2 plants per pot (low density), 4 plants per pot (medium density), and 12 plants per pot (high density). The results showed that water treatments, plant densities and their interaction significantly affected (P0.05) the total leaf area, total biomass per plant, main stem length, the total chlorophyll, carotenoid content, the ratios of chlorophyll a/chlorophyll b and total chlorophyll/carotenoid in C. Dactylon although the ratios of the chlorophyll a/chlorophyll b and total chlorophyll/carotenoid of each treatment can stay a normal level. Water treatment significantly affected (P0.05) the values of Fv/Fm, Fv/Fo and qP and the interaction of water treatments and plant densities significantly affected (P0.05) the values of qP although plant densities had little effect on fluorescence properties. These results suggested C. dactylon may be suitable for ecological restoration in the riparian zone with medium density.